Selective electrical signaling system.



0. L. GOODRUM. SELECTIVE ELECTRICAL SIGNALING SYSTEM.

APPLICATION FILED AUG. 8,1903;

Patented May 14, 1912.

UNITED STATES PATENT OFFICE.

. CHARLES LANE GOODRUM, F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGNMENTS, TO P. C. BURNS, OFCI-IICAGO, ILLINOIS.

SELECTIVE ELECTRICAL SIGNALING SYSTEM.

Specification of Letters Patent.

Patented May 14, 1912.

Application filed August 8, 1903. Serial No. 168,717.

the following is a specification.

My invention contemplates an improved construction and arrangement whereby a number of signaling devices, such as electric bells, and prcferably'six in number, may be connected at different points to a pair of line wires, andwhereby an operator, such, for example, as a telephone operator located at a different station, may ring any one of said bells at will without ringing the others.

My invention is applicable to signaling systems of various kinds, but it is more particularly adapted for use in connection with telephone systems, and especially in connection with whatare commonly known. as party line systems, it being necessary, as is well known, in telephone systems of this particular character, to locate several subscribers stations on one line.

Generally stated,the object of my invention is the provision of a simple, improved and highly eflicient selective signaling system.

A special object is to provide an improved construction and arrangement whereby at least six bells may be located on one party line, and whereby these bells may be operated on the well known plus and minus principle.

It is also an object to provide certain details and features of improvement tending to increase the general efiiciency and serviceability of a selective signaling system of this particular character. To the foregoing and other useful ends my invention consists in matters hereinafter set forth and claimed.

The accompanying figure is a diagram illustrating a selective electrical signaling system embodying the principles of my invention. I

As thus illustrated, my improved signaling system comprises a subscribers party line L and another and similarlin'c L lhese lines are connected at the central station with theusual springjacks J and J An operators cord circuit, provided with the usual answering'and callin in S g (i a.

and P is provided and employe well known manner as the-means for estati; lishing connection between the lines. Sub stations or subscribers" stations A, B, C,

D, E and F are connected with the line L- Similar substation. apparatus is connected with the llne L The said cord circuit is provided with ringing keys A B C D E and F whereby the different subscribers may be selectively signaled. For converi--;"' lence of illustration,'only the signaling apparatus and devices are shown, it being understood that the telephonic apparatus and as I instruments may be of any suitable, known or approved character.

The nature and advantages of my.im-

'proved selective signaling system will be best understood by considering the manner in which the operator calls up the difl'erent subscribers.

A ssummg that the operator desires to call subscriber A, the operation consists in insorting the plug corresponding to the set of selective keys in the spring jack J in the usual manner. The operator then depresses the A key to ringing'position, this closes a circuit from the negative pole of battery X, the other pole of said battery being grounded in any suitable manner, through conductor 1 to conductor 2, thence to contact point 3 of the selective key A, to the spring 4', to conductor 5 and strand 6 of the connecting plug, to the wire 7 of the subscribcfis line, thence to conductor 8 to the coil of the relay 9, by conductor 10 to the ground G which completes the circuit through the polarized relay 9. This relay is constructed more, it will be seen that when said circuits are completed, as described, an additional circuitis completed as follows: from the ion coil 28 of the station A, to contact point 29 and armature 30 of the relay 9, conductor 10 to ground G ."-.lhis circuit is completed by reason of the arn'iature 30 being att ractcd, as hereinbefore described, and thus closing the circuit at contact point 29, when the bell 28 responds to the current produced by the generator 19. It will be seen that the bells 63 and 85, which are connected to the same side of the line, will not ring for the reason that they are open to the ringing current at'the armatures 65 and 87 of the relays 12 and l5. At this time, the relay 12 remains in its normal condition, and the relay 15 attracts its armature, as previously described. It will be seen that the bells at the stations B, D and F will not ring for the reason that ringing current is not sup plied to that side of the line.

Should the operator desire to call the subscriber at the station marked B, she places the selective key B in the ringingposition, and thereby completes a number of circuits as follows: first, from the battery X, to

, conductor 1, to conductor 31, to spring 32, conductor 33, contact point 34, conductor 23,

conductor 24, cord strand 25 to line wire 26, conductor 35, coil 36 of the polarized relay at station B, conductor 37 to the ground G.

.Also from line wire 26 to conductor 38, coil 3901 the relay at station B, conductor 40, ground G; and from line wire. 26 to. conductor 41, coil 42 of the relay at station F, conductor 43, to ground G The relay 36 at stat-ion B is of the same construction as the relay-9 at station A and responding positively to negative currents, thus attracting -its armature 53. But the relay-39 being constructed to respond to positive currents, remains in its normal position; and relay 42 being constructed to respond to either positive or negative currents, attracts its'armatime 97. It will thus'be seen that a circuit is completed from the ground G to conductor 17, conductor 18, generator 19, conduct0r 20, conductor 44, to conductor 45, contact 46 of selective key B spring 47, conductor 48, contact 49, spring 4, conductor 5, cord strand 6, line Wire 7, conductor 50, the coils of the bell 51 at station B, by conductor 52 to armature 53 of'the relay at station B, conductor 37 and ground G the circuit being closed by means of armature 53 and the conductor 52, as hereinbefore described. It will be seen that the bells 73 and 95 will not ring, as the armature 75 of the relay 39 remains in its normal condition, and the armature 97 of the relay 42 is attracted, thus maintaining an open circuit to the bells 73 48, contact point 49, spring 4, conductor 5,

cord strand 6, linewire 7, conductor 8, coil 9, conductor '10 to ground (1 Also from line wire7 toconductor l1,coil -12 at station (I, conductor 13 to ground G and from line wire 7 to conductor 14, coil 15 at station E, conductor 16, to ground G The relay coil 9 being constructed to respond to a minus or negative current will now remain in its normal position, while relay 12 at station 0 be ng constructed torespond to a plus or positive current will attract its armature 65, which closes a circuit as follows: from the "ground G by conductor 17 to conductor 18,

to generator 19, to conductor 20, conductor 21, contact point 59 of selective key (7-, spring 60, contact 61, spring 32, conductor 33, contact point 34, spring 23, conductor 24-, cord strand 25, to line wire 26, to conductor 62, to the ringer coils of the bell 63 at station 0, to contact point 64, armature 65, conductor 13 to ground G thus completing the circuit through the bell 63 which now responds to the currentproduced by the generator19. It will be seen, that the bell 28 will not respond, as the circuit is open at contact point 29; also that the bell 85 will not respond, as the circuit is open at the armature 87 of the relay 15 at station E, .and as the armature 87 is attracted to its core by completion of a previously described circuit through said coil 15.

Assuming that the operator desires to call thesubscriber at station D', the operation is as follows: the operator depresses the selective key D to the ringing position, when circuits are completed as follows: from the pole of the battery Y, to the conductor 54, to contact point 66 of the selective key D, spring 67, contact 68, spring 60, conductor 61, spring 32, conductor 33 contact point 34, spring 23, conductor 24, cord strand 25, line wire 26, conductor 35, coil '56 of the relay at station E, conductor 37, to the ground G". Also from line wire 26 to conductor 38, coil 39 at station D, conductor 40 to ground G; and from line wire 26 to conductor 41, coil 42 of the relay at station F, conductor 43 to ground G. It will thus be seen that relay 36 at station B being constructed to respond tact point 58, spring 47, conductor 48,.con-

tact point 49 to spring 4, conductor 5, cord .strand 6, line 7, conductor 72, the coils oi the ringer 73 at station D, conductor 74, armature 75, conductor 40 to the ground G, when the bell 73 responds to the current produced by thegenerator. At this time.

' the bells51 and 95 will not respond to said current as a circuit is not completed through their coils, and as relay 36 remains in its normal condition, and relay 42 attracts its armature'97 on the completion of the circuit already described inconnection with the selective key D When the operator wishes to call sub. scriber E, she then depresses the selective key E to the ringing position, when circuits are completed as follows: from the ground G to conductor 76, conductor 77, contact point 78 of the selective key E spring. 79,

contact 80, spring 70, conductor 71, spring 57', contact point 58, spring 47 conductor 48, contact point 49, spring 4, conductor 5, cord strand 6, line wire 7, conductor 8, coil 9, conductor 10 to Gr; Also from line wire 7, to conductor 11, coil 12, conductor 13, ground G and fromjli'ne wire 7 to conductor 14, coil' '15, conductor 16 to ground G At this juncture, it will be seen that with these circuits there is no current flowing through the coils 9, 12 and 15, and that a circuit is completed through the bell 85 as follows: from, the ground G conductor 17, to conductor 18, generator .19, to con-. doctor 20, to contact point 81 of the selective key E, to spring 82, contact 83, spring 67 to contact 68, spring 60, conductor 61, spring32, conductor 33, contact point 34, spring 23, conductor 24, cord strand 25, line wire 26, conductor 84, the coils of the ringer 85 at station E, by conductor 86 to-arinature 87, conductor 16 to ground G when the bell 85 at station E responds to the current produced bythe generator 19.

Should the operator desire to call the sub scriber at station F, she depresses the selective key F to the ringing position, and thereby closes a number of circuits as follows from GT, conductor 17, to conductor 88, contact point- 89 of selective key F spring 90, contact 91, spring 82, contact 83,

spring67, contactspring 6 contact 61;, spring 32, conductor 33, contact point 34, spring 23, conductor 24, cord: strand 25, to linewire 26, conductor 41, }relay coil. 42,

' conductor 43 to ground G g also from line wire 26 to conductor 38, coil 39"bt' relay at station D, conductor 40 toqG, also from .line.wire 26, to conductor 35, coil 36 of relay at station B, conductor 37 to the ground G It will be seen that there isno current flowing through the coils 36, 39 and 42, and con-' sequently the relays of said station remain- 1 in their normal positions. A further circuit is closed through. hell 95 at station F as follows: from the ground G, conductor, 17 to conductor 18, generator 19, conductor" 20,'conductor 44, to spring 92 of lthe selective key F, contact 93-, spring 79, contact 80, spring :70, contact 71, spring 57, contact .point 58, spring 47, spring 48, contact point 49, spring 4, conductor 5, cord strand 6, line lectively signaling any one of these sub-.

scribers, and notwithstanding the fact that the signaling is done with positive and negative -currentsthat is to say, ,on the well known plus and minus principle.

It will be understood that the resistance of the various relays, and the construction of the various devices, can be modified or changed to suit the conditions of any particular case, and without departing'from the spirit of my invention.

What I'claim as my invention is:

1. A selective electrical signaling system, comprising a pair of line conductors, six sub-station equipments connected with said line conductors, each equipment including a relay and a bell, a spring jack connected with said line conductors, an operators cord circuit provided with sixringing keys, a grounded battery having its negative pole connected with the open contacts of two of said keys, another grounded battery ,having its positive pole connected with the open contacts of another pair of said keys, the relays at twov of said substations being adapted to be operated by minus current only, the relays attwo other substations being adapted to be operated by plus current only, and a generator having one pole connected with open contacts of all of said keys theother pole of said generator being grounded and also connected with open contacts of the remaining two keys, and the relay'svof the remaining "two substations being adapted to be-operated by'both plus and minus current substantially as set forth.

2. A selective electrical signaling system, comprising a pair of line conductors, six substation equipments connected with said line conductors, each of said equipments in-,

eluding a relayand a bell, the bell being connected with one line conductor and the relay with the other line conductor, a spring jack connected with said line conductors, an

operators cord circuit provided with a plug adapted to be inserted in said jack, said cord circuit being provided with six ringing keys, the relays at two substations being adapted to respond to minus currents, the relays attwo other substations being'adapted to respond to plus currents, the relays at the remaining two substations being responsive to both plus and minus currents, the apparatus by which the operator at the central station operates the system, for the purpose of calling the different subscribers, comprising a plurality of ringing keys, an alternating current ringing generator having one pole grounded, having both of its poles connected with said ringingkeys, and grounded ized relays and thereby close the circuits of batteries for supplying the plus and minus currents for energizing the relays, substantially as set forth.

3. A selective electrical signaling system, comprising a pair of line conductors, six substation equipments connected with said line conductors, each of said equipments including a relay and a bell, two of said relays being polarized and adapted to respond only to minus currents, two other of said relays being polarized and adapted to respond only to plus currents, the remaining two relays being responsive to both plus and minus currents, six ringing keys and means for connecting the same with the line conductors, so as to selectively energize said polarthe bells associated with these polarized relays, and at the same timeopen the circuits of the bells associated with the said remain ing two relays, the apparatus by which the operator at the central station operates the system, for the purpose of calling the difi'erent subscribers, comprising a plurality of ringing keys, an alternating current ringing generator having one pole grounded, having both of its poles connected with said ringing keys, andgrounded batteries for supplying the plus and minus currents for energizing the relays, substantially as set forth.

A selective electrical signaling system, comprising a pa r of line conductors, two polarized minus relays connected between the ground and opposite sides of the line circuit, two polarized plus relays connected between ground and opposite sides of the line circuit, two relays responsive to both plus and minus currents connected between ground and opposite sides of the line circuit, the apparatus by which the operator at the central station operates the system, for the purpose ofcallingthe different subscribers,

comprising a plurality of ringing keys, an alternating current ringing generator haw ing one pole grounded, having both of its poles connected with said ringing keys, and grounded batteries for supplying the plus and minus currents for energizing the re-- lays, substantially as set for h.

5. A telephone system comprising a central oliice, telephone lines leading therefrom, a series of calling instruments normally in circuit with said lines, a series of calling instruments normally out of circuit therewith,

and means controlled by central for cutting the first mentioned series of instruments out of circult with said lines and for cutting in circuit therewith the second mentioned series.

of instruments, the apparatus by which the operator at the central station operates the system, for the purpose of calling the different subscribers, comprising a plurality of ringing keys, an alternating current ringing generator having one pole grounded, having both of its poles connected with said ringing keys, and grounded batteries for supplying the plus and minus currents for energizing the relays, substantially as set forth.

6. A telephone system comprisin a central otiice, telephone lines, a series 0% callin instruments normally in circuit with sai lines and two series of calling instruments normally out of circuit with said lines, and means for cutting out of circuit with said lines the first mentioned series of instruments and simultaneously cutting in circuit with said lines either of the second mentioned series of instruments, the apparatus by which the operator at the central station operates the system, for the purpose of calling the different subscribers, comprising a plurality of ringing keys, an alternating current ringing generator having one pole grounded, having both of its poles connected with said ringing keys, and grounded batteries for supplying the plus and minus currents for energizing the relays, substantially as set forth.

7. A telephone system comprising a central ofiice, telephone lines leading therefrom, a series of calling instruments normally in circuit with one of said lines, a series of calling instruments normally out of circuit with one of said lines, and means controlled by central for cutting the first mentioned series of instruments out of circuit with their line and for cutting the second mentioned series of instruments into circuit-with their line, the apparatus by which the operator at the central station operates the system, for the purpose of calling the different subscribers, comprising a plurality of ringing keys, an alternating current ringing generator having one pole grounded, having both of its poles connected with said ringing keys, and

rinsed cofidugting pathlo ground, one or Signed by me at Philadelphia, Philadelnicre of said ringers having a normally open cenducimg path to ground, and means responslve to dlrect current flowmg over @i ther of said lines for initially closing the said normally open bridges and conducting gaths.

phia county, Pm, this first day f Augusb CHARLES LANE G-OODRUIQL Witnesses: M. 'S. LEWIS,

L. A. POTTEIGER. 

